I also need help removing the blank space from my website

Help! I can't figure out how to remove the blank spaces that show up as white between the last section and the pages footer. I built the site for a photographer (BobKiss.com) and the galeries range in size. A smaller page can look great when I edit it, but looking at it in a browser on a high resolution screen can show a lot of white space at the bottom. Each page started as a blank and I added sections for the headings, text and galleries.
Here are some pages with the problem:
https://www.bobkiss.com/personal-galleries-1
https://www.bobkiss.com/contact
Do I need some custom code, or am I just missing something?

It is fine to me. Can you take a screenshot?

Here they are, thank you.

The pages with more content (galleries with more than three rows) are not affected, But the pages with only one gallery row, or pages like the Contact Us page have the blank spaces above the footer. I've tried it at different window sizes on my 2160x3840 monitor and the size of the blank area changes, and in a small enough window it disappears.

Excellent. Changing the color of the blank areas eliminated the problem.

Thank you so much!